Adjustable dipole antenna



p 1962 c. J. ROGERS 3,052,883

ADJUSTABLE DIPOLE ANTENNA Filed Dec. 17, 1953 41 hmmmm gm .17 "kt I 26 J0 I I 20 I I ii i 21 1 1% i C I 2 12 2a" 22 2'2 25 V5 1. 70677%? 9 @arzv/Z r] ffye W 6 a Patented Sept. 4, 1962 Free 3,052,883 ADJUSTABLE DIPOLE ANTENNA Carroll J. Rogers, 7007 Sheridan Road, Chicago, Ill. Filed Dec. 17, 1953, Ser. No. 398,761 2 Claims. (Cl. 3438il2) The present invention relates generally to antennas, and more particularly it relates to electro-rnagnetic wave antennas. Specifically it relates to dipole antennas adapted to operate over a wide range of frequencies.

conventionally, dipole antennas are sized during the manufacture thereof to produce a maximum signal response at a frequency which corresponds to a wave length which is substantially at a median of the range for which the receiver is adapted. Because of the wide range of frequencies over which conventional signals are sent, dipole antennas lose effectiveness at frequencies difiering substantially from the one for which they are sized.

The provision of a dipole antenna having high frequency responses for all frequencies is especially important in television reception because of the wide range of frequencies being and to be utilized. Most critical is the requirement for dipole antennas adapted to give strong frequency and directional responses to ultra high frequency signals and being adapted to produce strong frequency and directional responses for the very high range of frequencies. The prior devices are not entirely satisfactory in this regard.

Those prior television dipole antennas adapted to be utilized in reception of all frequencies, including very high and ultra high frequencies are sized for two ranges of frequencies and therefore cannot induce maximum voltage at all frequencies.

The instant device not only is adapted to give maximum frequency and directional responses at all frequencies but is further adapted to effect substantial signal gain in an improved manner.

It is therefore one object of this invention to provide an improved dipole antenna having maximum efiectiveness at all selected frequencies.

it is a further object of this invention to provide a dipole antenna having optimum frequency and directional responses at all frequencies at which television waves are transmitted.

It is a still further object of this invention to provide, in a dipole antenna, novel signal gain means comprising a pair of conductors electrically connected to the dipole elements.

A yet further object of this invention is to provide a. dipole antenna in which the effective length of the dipole elements can be adjusted by rotation thereof.

Other and further objects of this invention will become apparent from the following description and appended claims, reference being had to the accompanying drawings and numerals of reference thereon.

On the drawings:

FIG. 1 is an elevational view of a preferred embodiment of the invention.

FIG. 2 is a top plan view of the embodiment illustrated in FIG. 1, portions being shown in section for the purpose of illustration.

P16. 3 is an enlarged vertical sectional View of the base.

FIG. 4 is a sectional view taken substantially on the line 4--4 of FIG. 3.

FIG. 5 is an enlarged detail view of the connection between the wire cage and the extensible sleeve at the inner end thereof.

FIG. 6 is an enlarged detail view illustrating the connection of the wire cage at the other end thereof.

Referring more particularly to the drawings, the base 10 may suitably comprise an attractively designed portable wood turning and optionally may be provided with a plurality of holes 11, 11 adapted to receive and hold the supports of ornaments such as artificial flowers and the like (not shown). The bottom 12 of base 10 is provided with a central recess 13 which communicatively connects with slot 14 in the wall of base 10 through which the lead in wire 15 extends.

in the embodiment of the invention illustrated in the drawings, base 10 has a centrally raised portion 16 above recess 13. Raised portion 16 is provided with a pair of spaced holes 17, 17 in which there are secured a pair of bushings 13, 18 that extend upwardly from base 10, as illustrated in the drawings.

One of a pair of metal connecting elements, known in the art as banana plugs 19, 19 is positioned in the bore 26 of each of the bushings 18, '18 and maintained and held at a desired height by engagement of collars 20, 29 with respective floors 21, 21 of holes 17, 17. Each of the plugs 19, 19 has a threaded metal shank 22 which extends from a respective collar 20 into recess 13, as illustrated in FIG. 3.

A pair of opposed lock nuts 23 and 24 is threaded on each of the shanks 22; and each pair of said lock nuts releasably secures therebetween one of the bare metal connectors 25 of the lead in wire 15, the upper lock nuts 23, 23 being threadable into engagement with the base it to hold the banana plugs 19, 19 rigidly erect.

The elongated outwardly extending portions 27, 27 form the dipole portions of the metal conductors 28, 28. Each of the metal conductors 28, 28 in the preferred form comprises a bent metal tube, the elongated lower portions 29, 29 of which provide supports for and are bent at substantially right angles from the outwardly extending elongated dipole portions 27, 27. The lower portions 29, 29, when in operative position, are substantially parallel to each other and each thereof is releasably and frictionally retained by a respective bushing 18 in contact with the rounded head 30 of 2. respective banana plug 19, as illustrated in FIG. 3.

The conductors 28, 28 are operably pivotable in the bushings 18, 18 yet are adapted to retain electrical contact with connectors 25, 25 because of the rounded heads 39, 30 of plugs 19, 19. To secure the conductors 28, 28 from undesired rotation and in selected positions a pressure lock is provided. The lock is preferably a fabrication of non-conductive material and comprises a strap 31 having a pair of apertures 32, 32 which are spaced from each other a distance less than the spacing between bores 26, as illustrated in FIG. 4. Therefore, when the lock 31 is moved toward the base 10, it causes successive tightening of the engagement of lower portions 29, 29 against the sides of bushings 19, 19, and when strap 31 is raised, the conductors 28, 28 become pivotable because of the inherent flexibility of the metal.

An elongated slideable conductive metal sleeve 33 is slidably mounted on each of the dipole portions 27, 27. The sleeves 33, 33 are extensible on respective dipole portions 27, 27 and are in electrical contact therewith when in operative position. Sleeves 33, 33 are preferably longer than dipole portions 27, 27 and may be telescoped inwardly or extended outwardly as illustrated in FIG. 1, or completely removed from said sleeves.

An elastic tension spring in the form of a helical cage 34 is mounted about each of the sleeves 33, 33. The inner end 35 of each cage 34 is secured in the slot 36 of a respective slotted metal cap or nut 37, as a result of the spring tension of a respective expanded cage 34. The metal caps 37, 37 are preferably threaded on the inner ends 38, 38 of respective sleeves 33, 33, as illustrated in FIG. 5. The opposite end 39 of each of the cages 34, 34 is removably mounted in a bore 40 of a respective metal plug 41. The metal plugs 41, 41 each have a shank 42 mum current flow in the antenna.

which extends into the bore 43 of an outer end 44 of a respective sleeve 33. The tension of cages 34, 34 on the plugs 41, 41 secures said plugs 41, 41 in operable position and in electrical contact with said sleeves 33, 33.

The device readily adapts itself to assembly at the place of use with a resultant economy in shipping and storing because it may be shipped and stored in the knocked down state. The cages 34, 34 are adapted to be removed from the sleeves 33, 33, the sleeves 33, 33 from the dipole portions 27, 27 and the conductors 28, 28, from the bushings 18, 18.

Because each of the dipole portions 27, 27 is pivotable at least 180 as illustrated in FIG. 2, the efiective length of the antenna broadside, or cutting electro-magnetic lines, of force in a given field may be reduced to nearly zero, thereby constituting the antenna, theoretically, capable of inducing a maximum voltage from a signal of nearly infinite frequency. That is to say, that as the dipole portions 27, 27, are moved together, their lineal eiiect in a given electro-magnetic field may be reduced to nearly zero. Whereas, when they are separated to the full line positions illustrated in FIGS. 1 and 2, the electro-magnetic field of a substantially lower frequency will cause a maxi- A still lower signal frequency may efiectively be received by extending the sleeves 33, 33. Between the positions indicated a myriad of other positionings of the dipole portions 27, 27 and sleeves 33, 33 are obtainable whereby maximum potential may be achieved by the antenna across an exceedingly wide range of frequencies depending upon the effective length of the dipoles.

The device may be used with or without the sleeves 33, 33 and the wire cages 34, 34. However, for any given effective dipole length, a greater voltage may be created when the cages 34, 34 are employed because the helical cages cut a greater number of lines of force in the electromagnetic field to thereby augment the potential created in the dipole portions 27, 27 as a result of the conduction of current from springs 34, 34 to said dipole portions; and because the impedence of the antenna is increased to correspond more closely to that for which a standard receiver is matched.

As many changes could be made in the described construction, and as many apparently widely difi'erent embodiments of this invention within the scope of the claims could be constructed without departing from the scope and spirit thereof, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative and not in a limiting sense.

I claim: v

1. An antenna system comprising a base, a pair of conductors having substantially parallel lower portions pivoted in said base, said conductors having outwardly extending lineally alignable upper portions; Wirecages electrically connected to said conductors respectively, said cages being extensibly mounted about the upper portions of said conductors and pressure lock means on said lower portions adapted to releasably secure said conductors in selected positions.

2. An antenna comprising a pair of pivoted bent metal conductors; a base, one end of each of said conductors being pivoted in said base, the outer end of said conductors being lineally alignable and being bent substantially ninety degrees from the first mentioned ends thereof; extensible sleeves extensibly mounted on the outer ends of said conductors and being electrically connectedthereto, and a metal spring about each of said outer ends, said metal springs being extensibly mounted about and electrically connected to said conductors.

References Cited in the file of this patent UNITED STATES PATENTS D. 155,113 Trebules Sept. 6, 1949 D. 156,399 Baldi Dec. 13, 1949 2,192,187 Gordon Mar. 5, 1940 2,495,579 Ferris Jan. 24, 1950 2,514,020 Wehner July 4, 1950 2,620,442 Trdbules Dec. 2, 1952 2,636,986 Riderman Apr. 28, 1953 2,657,311 Kleis Oct. 27, 1953 2,748,387 Klancnik May 29, 1956 OTHER REFERENCES Zaun: Abstract of application Serial Number 64,582, published January 8, 1952, in 654 O.G. 632. 

